! I'm really sorry you're going through all this. Try lowering the water level so he can reach the surface easily. Also, make sure he's in an almost dark environment, some say that helps the fish calm down and prevents the stress. I guess that's all you can do for now. Bettas are strong little fellas. I'm really hoping he'll get through this.

Sounds like swim bladder. Was their dechlorinator in the water your'e friend put in? He should be in a 2.5 gallon or more, Bowls are hard to heat and keep clean. He needs a heater that keeps a constant 78-80. Lower the water level. Sorry about your'e fish.